1. Field of the Invention
The present invention relates to an adjustment mode control method and an apparatus of performing the control method and, more particularly, to an adjustment mode control method in an image forming apparatus using electrophotographic method and the image forming apparatus.
2. Description of the Related Art
In an image forming apparatus such as a printing machine, copying machine, or printer, various types of adjustment operations for maintaining image quality at regular intervals based on the number of sheets that have passed through the image forming apparatus or an elapsed time are performed to maintain a certain level of image quality. Along with recent full-scale transition of image forming apparatuses from black-and-white to color, a number of adjustment operations performed during output operation to maintain image quality has been increasing. As a result, the proportion of the time for adjustment operations performed during output operation is becoming larger.
Accordingly, for example, even if a user wants to quickly produce a small number of output sheets, the user must wait to obtain the output sheets till adjustment operations performed during output operation have been finished.
Adjustment operations of an image forming apparatus are performed for the purpose of maintaining the highest image quality of an image forming apparatus. However, for certain users, the minimum image quality required to correctly read characters may be sufficient to produce an output which is naturally expected to be only confirmed and discarded later like a trial output for check. Thus, some users do not want an increase in output time caused by interrupts of adjustment operations during output operation.
As described above, there is demand for an image forming apparatus which can shorten output time by minimizing adjustment operations performed during output operation depending on a situation in which a user is placed, desired image quality, or user setting.
Against the background, conventional techniques for reducing the time for adjustment operations during output operation include in JPA 10-142857. In JPA 10-142857, when a timer exceeds a predetermined period of time, it is set to execute adjustment operation is at that time. However, if image formation operation is being executed when the timer has exceeded the predetermined period of time, the start of adjustment operation is delayed until the executed image formation operation finishes. This prevents adjustment operations of image forming conditions automatically performed from interfering with a user's image formation work. As described above, in JPA 10-142857, an image forming apparatus performs adjustment operations while it is not in output operation. This has the effect of minimizing the time for adjustment operations performed during output operation.
In JPA 2002-278177, in an image forming apparatus which performs image density adjustment operation, when it is set to inhibit image density adjustment operation, the apparatus does not perform image density adjustment operation.
However, in JPA 10-142857, adjustment operations for maintaining image quality are performed only while image formation operation is not performed. Accordingly, even when, e.g., output operation is produced in large quantity, adjustment operations cannot be performed during the output operation and then there are restrictions on maintaining image quality.
In JPA 2002-278177, adjustment operations are inhibited by settings made by a service operator with specialized knowledge. The intended object of JPA 2002-278177 is to provide a technique for shortening installation time for installing an image forming apparatus. If the same technique is applied to a general user and the user is allowed to arbitrarily inhibit adjustment operations, the user needs to determine whether or not to inhibit adjustment operations. It is difficult for the user to make such a determination and then the user may erroneously inhibit adjustment operations.
As has been described above, according to a conventional technique, the number of times of adjustment operation cannot be reduced by a user easily and optionally changing a timing at which adjustment operation is to be performed or by a user easily and optionally extending an interval to perform adjustment operations. Also, it is impossible for a user to easily and arbitrarily set an adjustment shortening mode in which the time for adjustment operations during image output operation is shortened by performing simple substitute adjustment operations to be on, depending on a situation in which the user is placed or desired image quality.
According to a conventional technique, it is impossible for a user to know in advance a time at which adjustment operation is to be performed during output operation before the user starts image output. For this reason, when a plurality of image forming apparatuses with the same specifications are placed, an apparatus which is to perform adjustment operation soon may be selected without a user's intention on a request to quickly produce several output sheets.
Even if an apparatus has the function of setting the adjustment shortening mode to be on, when a user cannot know in advance before starting image output that adjustment operation is to be performed during output operation, the user cannot determine whether or not to set the adjustment shortening mode to be on.